Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations indicate readOnlyHint=false, destructiveHint=false, idempotentHint=false. The description explains what the tool does but doesn't add meaningful behavioral context beyond the annotation flags. It doesn't say what happens on failure, whether it's idempotent in practice, or the effect of the mute_unarchive flag mentioned in the original WhatsApp API.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two short sentences plus a flattened action block. Efficient, though the 'flattened action' annotation introduces some redundancy with the action list mentioned in the first sentence.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a tool with 3 params and no output schema, the description covers the basic purpose but leaves gaps. The flattened action [unarchive] is useful context, but the parameter semantics and behavioral caveats are insufficiently documented.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 0% with 3 parameters, and the description adds no parameter-level detail beyond implying chat_jid is required. The description mentions 'Requires chat_jid' which is helpful, but gives no guidance on account, duration_secs, or how to control the action.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states 'Change a chat's state. action: archive/unarchive, pin/unpin, mute/unmute. Requires chat_jid.' which clearly indicates it's a state-change tool. However, the description is generic and doesn't specifically call out 'unarchive' until the flattened action. It's clear but could be more specific about what unarchiving does.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies the tool handles multiple state changes, but doesn't explicitly distinguish when to use this versus siblings like whatsapp_chat_archive. It doesn't explain the routing logic (how the system decides which action to take) or when a caller would choose this specific unarchive tool over others.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.